In a known lightning conductor system for a wind turbine a gap in the lightning down-conductor between a pitchable rotor blade and the wind turbine's nacelle—two parts which are rotatable relative to each other—is bridged by a lightning current transfer arrangement having sliding contacts which contact complementary slideways, as described in WO 2005/050008 A1. The sliding contacts include a contact rod which provides the electric contact with the slideway, and a slide pad surrounding the contact rod to increase the sliding surface and lower sliding friction.
Other types of sliding contacts for wind turbines with in the form of metal or carbon brushes are known, e.g. from WO 2004/001224 A1.
U.S. Pat. No. 7,390,169 B2 describes a lightning current transfer arrangement for a wind turbine having a sliding contact and a spark gap towards a contact member. The sliding contact and the spark gap are connected in parallel.